Beginner
The first skill to know is using four straight lines to draw a square. Use the right knob to draw vertical lines and the left for horizontal, learning which way to turn them to make the line go up or down. Practice making boxes of different sizes. Another basic used a lot is retracing drawn lines to get back to your starting point. It sounds simple but it's easy to go off the line. Start by drawing and retracing a 1-inch line, then move on to longer lines. Diagonal lines are next. For lines going left to right, turn both knobs in the same direction. For right to left diagonals, turn the knobs in toward each other.
Intermediate
The Etch A Sketch artist who has mastered drawing and retracing straight lines can use that skill to create something with square shapes like a skyline of a city. Draw buildings by making connected rectangles of different sizes and shapes. Use diagonal lines to make triangle. This takes patience to learn when to turn the knobs away from each other or in the same direction. The next shape to learn is the circle. Start off by twisting both knobs to the right, then make the curve of the circle by turning them toward each other. Then turn both left for the bottom of the circle, and away from each other to create the final curve. Practice triangles and circles of different sizes.
Advanced
With the ability to create all these individual shapes, it's now possible to draw almost anything. A good place to start might be a house. Draw a square for the main part of the house and use your ability to draw diagonal lines to make a triangular roof. Use small squares and rectangles to draw doors and windows. Another advanced Etch A Sketch skill is shading. Practice by first drawing a square, then beginning on the left side of the square, turn the right knob up and down to make vertical lines while turning the left knob slightly to keep the shading moving across the square.